Probability without Modals: Likely, Bound, Definitely
Express how sure you are about the future using phrases and adverbs.
- check_circleI can use 'be likely to' and 'be unlikely to' to talk about probability.
- check_circleI can use 'be bound to' for things that are almost certain.
- check_circleI can correctly place adverbs of probability like 'probably' and 'definitely'.
Discover
Meet today's English in a real situation — no rules yet. Read it once and try to guess the pattern in the words in bold. Underlined words open a short definition.
Sam: Hey, do you think we’ll finish the project by Friday? Tina: Well, we are likely to finish the main parts, but I don’t think we’ll have time for the extra features. Sam: Yeah, that’s probably true. Do you think the boss will be mad? Tina: He is bound to be a little disappointed, but if we explain the situation, he will definitely understand. Sam: I hope so. It’s highly unlikely that anyone else could have done it faster. Tina: Exactly. We’ll definitely have a working version to show him.
Learn
Now the rules behind what you just saw — explained simply, with examples. Underlined words open a short definition — hover on desktop, tap on a phone.
We often use modal verbs (like might, may, or will) to talk about the future, but we can also use specific adjectives and adverbs to express how probable something is.
Be likely to / Be unlikely to
When something is probable, we say it is likely. When it is not probable, it is unlikely. Notice that these are adjectives, not verbs, so we use them with the verb to be.
The formula is: Subject + be + (un)likely + to + infinitive verb
- She is likely to succeed in her new job. (It’s probable that she will succeed.)
- We are unlikely to arrive before 8 PM. (It’s not probable that we will arrive.)
- It is highly likely to rain tomorrow.
You can also use the structure: It is (un)likely that + clause.
- It is likely that she will succeed.
Be bound to
If you are almost 100% certain that something will happen, use be bound to. It carries a strong sense of inevitability.
- Don’t worry, you are bound to pass the exam. You’ve studied so hard!
- He is bound to notice that the car is scratched.
Adverbs of Probability: Probably and Definitely
We use adverbs like probably (very likely) and definitely (100% certain) to show how sure we are. However, their position in the sentence is very important!
With affirmative sentences (will): The adverb goes after will (or the auxiliary verb) and before the main verb.
- I will definitely go to the party.
- She has probably left by now.
With negative sentences (won’t): The adverb goes before won’t.
- I definitely won’t go to the party.
- They probably won’t win the game.
Common mistake: Do not place the adverb at the beginning of the sentence if you are using will or won’t.
Probably I will go to the gym later.- I will probably go to the gym later.
Definitely she won’t like this idea.- She definitely won’t like this idea.
You can also use these adverbs with the verb to be:
- He is definitely the best player on the team.
- The traffic is probably bad right now.
Let’s look at one more adverb: certainly. It follows the exact same rules as definitely.
- likely / unlikely: Use with the verb to be + to + infinitive (e.g., I am likely to go).
- bound to: Use for things you are almost 100% sure will happen (e.g., It’s bound to rain).
- Affirmative adverbs: Place them after the first auxiliary verb (e.g., She will probably arrive soon).
- Negative adverbs: Place them before the negative auxiliary verb (e.g., They definitely won’t like it).
Practice
Try it yourself. You'll see right away whether you got it right, plus a short explanation of why.
Use It
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Before you finish — be honest. Can you do these now?